NEET 2026
- Exam
- NEET
- Year
- 2026
- Subject
- Chemistry
- Chapter
- Chapter
NEET 2026 · Chemistry · Chapter
The given P-V graph illustrates the reversible isothermal expansion...
The given graph illustrates the reversible isothermal expansion of a fixed amount of an ideal gas from an initial volume to a final volume at two different constant temperatures, and . Let and be the magnitudes of the work done by the gas during the expansion at temperatures and , respectively. Based on the graph, which of the following statements is correct?
Options
- A because the area under the curve at is greater than the area under the curve at .
- B because the gas exerts less pressure at lower temperatures, allowing for easier expansion.
- C because the change in volume () is identical for both processes.
- D because the change in internal energy () is zero for any isothermal process of an ideal gas.
Correct answer
A. because the area under the curve at is greater than the area under the curve at .
Step-by-step solution
The work done by a gas during a reversible expansion is given by the area under the curve, which is mathematically represented as .
From the given graph, it is evident that the isotherm for temperature lies above the isotherm for temperature . This means that for any given volume between and , the pressure at is greater than the pressure at .
Consequently, the area under the curve at is greater than the area under the curve at .
Therefore, the magnitude of the work done at is greater than the magnitude of the work done at , i.e., .
Answer: because the area under the curve at is greater than the area under the curve at .
From the given graph, it is evident that the isotherm for temperature lies above the isotherm for temperature . This means that for any given volume between and , the pressure at is greater than the pressure at .
Consequently, the area under the curve at is greater than the area under the curve at .
Therefore, the magnitude of the work done at is greater than the magnitude of the work done at , i.e., .
Answer: because the area under the curve at is greater than the area under the curve at .